In the use of typical automotive utility trailers such as boat, cargo, camping, horse, race car, or work trailers it is critical for safe towing to have the proper distribution of weight between the hitch on the towing vehicle and the axle[s] of the trailer. If the weight on the hitch is too small, the trailer will shimmy and sway possibly causing loss of control and an accident. If the weight is too high on the hitch, then the rear of the tow vehicle is over loaded and the steering wheels and brakes are less effective, which will lead to control and stopping problems. Proper trailer loading and weight distribution helps ensure proper and safe trailer handling.
At the present time there are no convenient and accurate ways for a user to determine whether the trailer is properly loaded. For example, one conventional way to measure this weight distribution is for the user to guesstimate it themselves. This is particularly true in the case of all rental style cargo trailers where untrained people who are not familiar with the requirements of towing are doing the loading. Even in the case of travel and boat trailers where the manufacturer has provided the trailer and properly balanced it, the user can upset that balance by how they load additional equipment into the boat or trailer.
Another conventional means for obtaining the tongue weight on trailers is a separate weight scale that may be placed under the trailer tongue. One example includes the Sherline Trailer Tongue Weight Scale (see. e.g., http://www.sherline.com/lm.htm). The Sherline scale uses a hydraulic principle to convert weight into a direct reading on a hydraulic pressure gauge.
An accurate measurement of tongue weight may be achieved by measuring right where the hitch actually rests on the ball or alternatively at the tongue jack. The Sherline scale uses an extension that screws into the top of the cylinder so that the trailer hitch may be supported. The Sherline scale teaches that it is best practice to measure the hitch weight with the trailer level (trailer wheels blocked to prevent movement) and the hitch at the approximate height it will be when installed on the tow vehicle.
The trailer tongue may be supported with the tongue jack. Blocks are required to be used with the Sherline scale to block the Sherline scale into position under the hitch. The Sherline scale teaches that, alternatively, a hydraulic floor jack may be used and the Sherline scale may be placed on the jack and jacked into position. The tongue jack may be raised until the full weight of the hitch is on the Sherline scale and the weight in pounds may be read directly from the gauge on the Sherline scale.
As such the Sherline scale suffers from the drawbacks that it is a standalone device that must be separately carried around and also from the fact that separate and ancillary devices (e.g., wood blocks or a hydraulic floor jack) are required to properly place and use the Sherline scale.
Thus, there is a need for a trailer weight measurement system that is accurate and easy to use. What is needed is a simple and effective means for determining whether a trailer is properly loaded for safe handling when being towed by a tow vehicle. What is needed is a simple and effective means of determining the weight on the trailer tongue without having to carry and use separate devices.